1) Technical Field
The subject invention relates to a container filling assembly for filling a plurality of containers with a product in a sterile environment.
2) Description of the Prior Art
In the beverage industry, containers, which can include aluminum, glass, or plastic cans or bottles, are typically filled with a product through a valve filling station. The products can include fruit juices, carbonated beverages, water and the like. The prior art valve filling stations operate effectively for aluminum cans, glass bottles and for plastic bottles having sufficient rigidity.
Many of today's plastic bottles, however, include relatively thin walls with a rigid annular neck having a threaded top. The thin walls have a tendency to collapse, expand and/or balloon during the filling process. The collapsing and ballooning of the bottles is undesirable for a number of reasons. First, the accuracy of the filling is compromised. Also, the bottle will have an aesthetically displeasing shape. These types of plastic bottles are typically called PET bottles and are available in a variety of sizes, such as 12 oz., 20 oz., and 1 liter. The plastic bottles are typically carried through a container filling assembly by a neck ring on the rigid annular neck.
It is desirable to eliminate the collapsing, expanding and/or ballooning of the PET bottles during the filling process. One contemplated solution simultaneously maintains equal pressure within the bottle and around the exterior of the bottle. This can be accomplished by creating a sealed chamber around the bottle. The sealed chamber also maintains a sterile environment, i.e., free of bacteria, around the exterior of the bottle and assists in maintaining the sterile environment within the bottle.
This solution has been contemplated by the prior art. Specifically, U.S. Pat. Nos. 2,885,845 and 5,031,673 disclose such a solution. These prior art patents include a valve filling station having a fixedly secured downwardly projecting enclosure. The container rests upon a base which moves vertically to position the container within the enclosure. The base then seals with the bottom section of the enclosure. Another solution contemplated by the prior art is shown in British Patent No. 1,212,503. This filling mechanism has a moveable enclosure along with a moveable base. The enclosure extends below the base during the insertion and removal of the containers. The bottle is placed onto the base and then the enclosure and base move upward to fill the container. These prior art designs, however, have a number of deficiencies.
One of the primary deficiencies is the prior art designs have not contemplated the new PET bottles which are carried by the neck through the container filling assembly. The continuous movement of the base carrying the bottle creates excessive wear on the filling mechanism. Current methods of performing filling operations with the light weight PET bottles is not as efficient as desired. Further, many of these prior art designs have difficulty accommodating different size containers.
Hence, it is desirable to have a container filling assembly which incorporates an enclosure for creating a sealed chamber around a PET bottle such that the PET bottle does not balloon or collapse during the filling process. It is also desirable to have a container filling assembly which can accommodate different size bottles.